Participants of many sports, including baseball, football, soccer, hockey, tennis, and golf, and their coaches, are often interested in knowing the motion characteristics of the object used in a sport, such as the distance, time of flight, speed, height, spin rate, or curve of thrown, kicked, or batted balls and slapped hockey pucks. Typically, the speed of a moving ball is measured using a Doppler radar system. Doppler radar systems determine a moving ball's speed by analyzing radar beams reflected off the ball. Although accurate, these systems are expensive and normally cannot be operated by the athlete whose toss or hit is being measured. For these reasons, systems of this type are generally restricted to organized sport teams. Also, Doppler radar systems are not able to measure the spin rate of the ball of interest. Spin rate information is useful for example in optimizing a baseball pitcher's curve ball pitching ability.
Several other methods for measuring the motion characteristics of moving objects have been proposed over the years that rely on devices wholly external to the moving object. Another approach to the problem involves placing a measurement device within the moving object. Two such systems are described in U.S. Pat. No. 4,775,948 issued on Oct. 4, 1988 to Dial et al. entitled "Baseball Having Inherent Speed-Measuring Capabilities", the '948 patent, and U.S. Pat. No. 5,526,326 issued on Jun. 11, 1996 to Fekete et al. entitled "Speed Indicating Ball", the '326 patent. The '948 patent involves placing an electronic timer and calculator within the ball. The timer measures the ball's time of flight over a measured distance, and on that basis determines the ball's speed. It then displays the speed on the surface of the ball via a liquid crystal display. The '326 patent suggests that a more economical and durable method of accomplishing the same task is met by using mechanical means internal to a ball for determining time of flight and speed.
Neither of these systems previously proposed, however, combine the desirable characteristics of being economical, durable, simple to operate by the athlete, and transparent to that athlete in terms of the feel of the ball and the ball's flight performance. And neither of the systems proposed are able to measure the ball's spin rate or curve. The embedded electronic timer with an LCD display proposed in the '948 patent is vulnerable to strikes against the ground, a glove, or a bat, and is very difficult to manufacture without altering the balance, feel, and flight performance of a ball. The mechanical solution proposed in the '326 patent claims to be more durable, but alters a ball's physical characteristics even more because of its voluminous design. In addition, it splits a ball into two halves that must be wound relative to each other by the player. The two halves must be held in this position until released in a toss. This design is not transparent to the user and alters the physical structure, balance, and flight performance of a ball significantly. Also, the mechanical design cannot be applied to moving objects that are not held by a player, such as a hockey puck.
It is thus apparent that there is a need in the art for an improved measuring method or apparatus which does not significantly or materially alter the moving object in question's physical characteristics or flight performance, is inexpensive, durable, applicable to many different types of sports equipment and other movable objects, measures many different motion characteristics, and is operable by the person doing the throwing, kicking, hitting, or batting. The present invention meets these and other needs in the art.
This application is related to application Ser. No. 09/007,240 of Dave Marinelli filed on Jan. 14, 1998 entitled A Time of Motion, Speed, and Trajectory Height Measuring Device, which is incorporated herein by reference for all that is disclosed and taught therein.